There is nothing to say against backgrounds, but in my opinion they shouldn't be opaque but halt transparent. So you can achieve both: Don't lose data (even so it is harder to see them) with better readability of the icons. Bringing it to the edge, the background transparancy could be adjustable via settings.

I already pointed out, that @mosen did already make an, at least for me, nearly perfect proposal:
http://talk.maemo.org/showpost.php?p...&postcount=378
(Here for me also the search icon was great - especially with breaking out from that background )